Custom "Gong" ringtone?

Does anyone know of a really deep, long standing wave, bronze "gong" sound that I can use as either an custom alert or ringtone? I'm looking for something like you'd hear from the big bronze bell bell you might see in a Buddhist temple.

I've seen a number of apps (both free a & paid) that generate various gong tones, but usually as a standalone game or app and I'm looking for a definite ringtone/alert tone.